FIG. 1 illustrates one type of convention video line driver 110, which is powered by both an external positive power supply 120 (e.g., +5V) and an external negative power supply 122 (e.g., −5V). This is disadvantageous because it is more expensive to provide two external power supplies (i.e., a positive and a negative power supply) than to provide a single external power supply. Additionally, the dual power supply video line driver 110 draws more power than one that uses a single power supply.
FIG. 2 illustrates another type of convention video line driver 210, which is powered by a single external power supply 220 (e.g., +5V), but requires very large external capacitors (e.g., 470 uF) on the output to get rid of the DC offsets that occur when using a single voltage supply. This is disadvantageous because capacitors having a high capacitance are physically large as well as expensive.
It would be advantageous if the above mentioned disadvantages of conventional video line drivers could be overcome.